Gael g



(No Model.)

0. G. HARSTROM.

WATCH GASE SPRING.

'- No. 376,524. Patented Jan. 17, 1888.

INK/ENTER I ATTZEJ? ilbn 14 W X W f UNITED STATES PATENT. OFFICE.

CARL G. HARSTRCM, OF PEEKSKILL, NEW YORK.

WATCH-CASE SPRING.

SPECIFICATION forming part of Letters Patent No. 376,524 dated January 17, 1888.

7 Application filed February 23, 1887. Serial No. 228,005. (No model.)

To all whom it may concern:

Be it known that I, CARL G. HARSTRiiM, a citizen of the United States, residing at Peekskill, in the county of Westchester and State of New York, have invented a new and useful Improvement in Watch-Case Springs, of which the following is a specification.

My invention relates to that class of watchcase springs which consist of two parts-i. 0., a spring of wire supported in a rigid holder, and has for its object the overcoming .of mechanical diificulties that have made such springs either as unreliable as the old forms of springs or unprofitable to manufacture. I attain the object by the means illustrated in the accompanying drawings, in which similar letters edge of the spring-holder.

1 provided with the solid projection d and the slotted projections c and b, as shown in Figs. 1, 2, 3. Heretofore the projections 0 and b have been made solid, with holes drilled longitudinally through them for the introduction of the spring D therein. The difficulty and eX- pense attendant upon the drilling of the said holes have practically made the manufacture of the springs a failure commercially. Instead,

therefore, of drilling these projections c and b, I. out slots through them, as shown in Fig. 3

and sectional Fig. 4.

The spring D, I make, preferably, of pianowire, although any good hard-drawn steel or elastic wire may be used for the purpose. The wire 'is reduced to a semicircular form, as

A shown in cross-section, Fig. 4., and the bottoms of the slots, through c and b, are adapted to the form of the spring.

When the spring D is set in its place within the slots 0 and b, pressure is applied to the projections and they are closed over the spring, as represented at e in the cross-section, Fig. 4.. The projections aremade to embrace the spring closely, but with a pressure that willadmit of the longitudinal adjustment of the spring that is, referring to Fig. 3, in which the spring is represented by dotted lines D, when the projections c and b are closed over the spring the spring may still be moved between them from right to left. When the springD is thus secured in its place, the projections b and c, with the solid projection (2, form a bead that fits within a groove that is made within the edge of the watch-cases. A screw secures the holder B in the case, as at a, Fig. 1. The holder B being thus held firmly in place, the wire D is as rigidly secure, and the torsional strain put upon the spring by means of the pressure on the spring-point f, Fig. 1, gives thespring-power for operating the lid of the watch-case.

Having described my inventiomwhat I desire to-claim, and secure by Letters Patent, is-

1. In a watch-case spring, the combination of a spring, D, and a spring-holder, B, provided with projections c c and b b, bent over upon the spring, holding said spring firmly in its place yet admitting ofits lateral adj ustment. substantially as herein shown and described.

2. The combination, in a watchcase spring, of a wire spring, D, semicircular in cross-section, and a holder, B, having projections c c and b b bent over upon the spring to secure it in place, substantially as herein shown and described. n

' CARL G. HARSTROM.

Witnesses:

STEPHEN LENT, EDWARD G. HALSEY. 

